Dogs naturally want to reassure humans in distress, and not just their owners, scientists believe.
British researchers filmed 18 dogs of various breeds in their homes. Their owner, then a stranger started to talk, hum loudly, then pretend to cry.
All but three of the dogs stopped what they were doing and approached the distressed person submissively, then touched them in a reassuring way even when it was the stranger.
Lead author Jennifer Mayer said this is relatively sophisticated behaviour which puts dogs on a par with toddlers, who will try to comfort someone in distress by hugging them or giving them a toy.
"Regardless of whether it was their owner or the stranger, when an individual cried most of the dogs went up to them in a quiet, submissive way suggesting comfort-giving," Mayer said.